System and method for distributed multi-processing security gateway

ABSTRACT

A system and method for a distributed multi-processing security gateway establishes a host side session, selects a proxy network address for a server, uses the proxy network address to establish a server side session, receives a data packet, assigns a central processing unit core from a plurality of central processing unit cores in a multi-core processor of the security gateway to process the data packet, processes the data packet according to security policies, and sends the processed data packet. The proxy network address is selected such that a same central processing unit core is assigned to process data packets from the server side session and the host side session. By assigning central processing unit cores in this manner, higher capable security gateways are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending U.S. patentapplication entitled “System and Method for Distributed Multi-ProcessingSecurity Gateway”, Ser. No. 11/501,607, filed on Aug. 8, 2006.

BACKGROUND

1. Field

This invention relates generally to data networking, and morespecifically, to a system and method for a distributed multi-processingsecurity gateway.

2. Related Art

Data network activities increases as more and more computers areconnected through data networks, and more and more applications utilizethe data networks for their functions. Therefore, it becomes moreimportant to protect the data network against security breaches.

There are currently many security gateways such as firewalls, VPNfirewalls, parental control appliances, email virus detection gateways,special gateways for phishing and spyware, intrusion detection andprevention appliances, access control gateways, identity managementgateways, and many other types of security gateways. These products aretypically implemented using a general purpose micro-processor such asIntel Pentium, an AMD processor or a SPARC processor, or an embeddedmicro-processor based on RISC architecture such as MIPS architecture,PowerPC architecture, or ARM architecture.

Micro-processor architectures are limited in their processingcapability. Typically they are capable of handling up to a gigabit persecond of bandwidth. In the past few years, data network bandwidthutilization increases at a pace faster than improvements ofmicro-processor capabilities. Today, it is not uncommon to seemulti-gigabit per second of data network bandwidth utilization in manymedium and large secure corporate data networks. It is expected suchscenarios to become more prevailing in most data networks, includingsmall business data network, residential networks, and service providerdata networks.

The trend in the increasing usage of data networks illustrates a needfor better and higher capable security gateways, particularly in usingmultiple processing elements, each being a micro-processor or based onmicro-processing architecture, to work in tandem to protect the datanetworks.

SUMMARY

A system and method for a distributed multi-processing security gatewayestablishes a host side session, selects a proxy network address for aserver, uses the proxy network address to establish a server sidesession, receives a data packet, assigns a central processing unit corefrom a plurality of central processing unit cores in a multi-coreprocessor of the security gateway to process the data packet, processesthe data packet according to security policies, and sends the processeddata packet. The proxy network address is selected such that a samecentral processing unit core is assigned to process data packets fromthe server side session and the host side session. By assigning centralprocessing unit cores in this manner, higher capable security gatewaysare provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 a illustrates a secure data network.

FIG. 1 b illustrates an overview of a network address translation (NAT)process.

FIG. 1 illustrates a NAT process for a TCP session.

FIG. 2 illustrates a distributed multi-processing security gateway.

FIG. 3 illustrates a dispatching process.

FIG. 4 illustrates a proxy network address selection process.

FIG. 5 illustrates a multi-processor core embodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 a illustrates a secure data network. Security gateway 170protects a secure data network 199.

In one embodiment, secure data network 199 is a residential datanetwork. In one embodiment, secure data network 199 is a corporatenetwork. In one embodiment, secure data network 199 is a regionalcorporate network. In one embodiment, secure data network 199 is aservice provider network.

In one embodiment, security gateway 170 is a residential broadbandgateway. In one embodiment, security gateway 170 is a corporatefirewall. In one embodiment, security gateway 170 is a regional officefirewall or a department firewall. In one embodiment, security gateway170 is a corporate virtual private network (VPN) firewall. In oneembodiment, security gateway 170 is an Internet gateway of a serviceprovider network.

When host 130 inside secure data network 199 accesses a server 110outside secure data network 199, host 130 establishes a session withserver 110 through security gateway 170. Data packets exchanged withinthe session, between host 130 and server 110, pass through securitygateway 170. Security gateway 170 applies a plurality of securitypolicies during processing of the data packets within the session.Examples of security policies include network address protection,content filtering, virus detection and infestation prevention, spywareor phishing blocking, network intrusion or denial of service prevention,data traffic monitoring, or data traffic interception.

FIG. 1 b illustrates an overview of a network address translation (NAT)process.

In one embodiment, a security policy is to protect network address ofhost 130. Host 130 uses a host network address 183 in a session 160between host 130 and server 110. In one embodiment, the host networkaddress 183 includes an IP address of host 130. In another embodiment,the host network address 183 includes a session port address of host130.

Security gateway 170 protects host 130 by not revealing the host networkaddress 183. When host 130 sends a session request for session 160 tosecurity gateway 170, the session request includes host network address183.

Security gateway 170 establishes host side session 169 with host 130.Host 130 uses host network address 183 in session 169.

Security gateway 170 selects a proxy network address 187. Securitygateway 170 uses proxy network address 187 to establish server sidesession 165 with server 110.

Server side session 165 is the session between security gateway 170 andserver 110. Host side session 169 is the session between securitygateway 170 and host 130. Session 160 includes server side session 165and host side session 169.

Security gateway 170 performs network address translation (NAT) processon session 160. Security gateway 170 performs network addresstranslation process on data packets received on server side session 165by substituting proxy network address 187 with host network address 183.Security gateway 170 transmits the translated data packets onto hostside session 169. Similarly, security gateway 170 performs networkaddress translation process on data packets received on host sidesession 169 by substituting host network address 183 with proxy networkaddress 187. Security gateway 170 transmits the translated data packetsonto server side session 165.

In one embodiment, session 160 is a transmission control protocol (TCP)session. In one embodiment, session 160 is a user datagram protocol(UDP) session. In one embodiment, session 160 is an internet controlmessaging protocol (ICMP) session. In one embodiment, session 160 isbased on a transport session protocol on top of IP protocol. In oneembodiment, session 160 is based on an application session protocol ontop of IP protocol.

FIG. 1 c illustrates a NAT process for a TCP session.

Host 130 sends a session request 192 for establishing a session 160 withserver 110. Session 160 is a TCP session. Session request 192 includeshost network address 183 and server network address 184. Securitygateway 170 receives session request 192. Security gateway 170 extractshost network address 183 from session request 192. Security gateway 170determines a proxy network address 187. In one embodiment, host networkaddress 183 includes a host's IP address, and security gateway 170determines a proxy IP address to substitute host's IP address. In oneembodiment, host network address 183 includes a host's TCP port number,and security gateway 170 determines a proxy TCP port number tosubstitute host's TCP port number. Security gateway 170 extracts servernetwork address 184 from session request 192. Security gateway 170establishes a server side session 165 with server 110 based on servernetwork address 184 and proxy network address 187. Server side session165 is a TCP session.

Security gateway 170 also establishes a host side session 169 with host130 by responding to session request 192.

After establishing server side session 165 and host side session 169,security gateway 170 processes data packets from server side session 165and host side session 169.

In one embodiment, security gateway 170 receives a data packet 185 fromserver side session 165. Data packet 185 includes server network address184 and proxy network address 187. Security gateway 170 extracts servernetwork address 184 and proxy network address 187. Security gateway 170determines host side session 169 based on the extracted networkaddresses. Security gateway 170 further determines host network address183 from host side session 169. Security gateway 170 modifies datapacket 185 by first substituting proxy network address 187 with hostnetwork address 183. Security gateway 170 modifies other parts of datapacket 185, such as TCP checksum, IP header checksum. In one embodiment,security gateway 170 modifies payload of data packet 185 by substitutingany usage of proxy network address 187 with host network address 183.

After security gateway 170 completes modifying data packet 185, securitygateway 170 transmits the modified data packet 185 onto host sidesession 169.

In a similar fashion, security gateway 170 receives a data packet 188from host side session 169. Data packet 188 includes server networkaddress 184 and host network address 183. Security gateway 170 extractsserver network address 184 and host network address 183. Securitygateway 170 determines server side session 165 based on the extractednetwork addresses. Security gateway 170 further determines proxy networkaddress 187 from server side session 165. Security gateway 170 modifiesdata packet 188 by first substituting host network address 183 withproxy network address 187. Security gateway 170 modifies other parts ofdata packet 188, such as TCP checksum, IP header checksum. In oneembodiment, security gateway 170 modifies payload of data packet 188 bysubstituting any usage of host network address 183 with proxy networkaddress 187.

After security gateway 170 completes modifying data packet 188, securitygateway 170 transmits the modified data packet 188 onto server sidesession 165.

FIG. 2 illustrates a distributed multi-processing security gateway.

In one embodiment, security gateway 270 is a distributedmulti-processing system. Security gateway 270 includes a plurality ofprocessing elements. A processing element 272 includes a memory module.The memory module stores host network addresses, proxy network addressesand other information for processing element 272 to apply securitypolicies as described in FIG. 1. Processing element 272 has a processingelement identity 273.

In one embodiment illustrated in FIG. 5, processing element 272 is acentral processing unit (CPU) core 572 in a multi-core processor 579which combines two or more independent cores. In one embodiment,multi-core processor 579 is a dual-core processor such as Intel's Core 2Duo processor, or AMD's Athlon dual-core processor. In one embodiment,multi-core processor 579 is a quad-core processor such as Intel'squad-core Xeon 5300 series processor, or AMD's Opteron Quad-Coreprocessor.

In one embodiment, security gateway 270 includes a plurality ofmulti-core processors, wherein processing element 272 is a multi-coreprocessor.

In one embodiment, processing element 272 is a packet processing modulewithin a network processor, such as Intel's IXP2855 or IXP2805 networkprocessor. AMD's Au1500 processor, or Cavium's Octeon MIPS64 networkprocessor.

Security gateway 270 includes a dispatcher 275. Dispatcher 275 receivesa data packet and determines a processing element to process the datapacket. Dispatcher 275 typically calculates a processing elementidentity based on the data packet. Based on the calculated processingelement identity, security gateway 270 assigns the data packet to theidentified processing element for processing.

In one embodiment, dispatcher 275 receives a data packet 288 from hostside session 269 and calculates a first processing element identitybased on the host network address and server network address in datapacket 288. In another embodiment dispatcher 275 receives a data packet285 from server side session 265 and calculates a second processingelement identity based on the proxy network address and server networkaddress in data packet 285.

Security gateway 270 includes a network address selector 277. Networkaddress selector 277 selects a proxy network address based on networkinformation. The network information includes a host network addressobtained in a session request for session 260 and a security gatewaynetwork address. Other types of network information may also be used.The proxy network address is used to establish server side session 265.The proxy network address is selected such that the first processingelement identity and the second processing element identity calculatedby dispatcher 275 are the same. In other words, a same processingelement is assigned to process data packet 285 from server side session265 and data packet 288 from host side session 269.

In one embodiment, the proxy network address is selected such that thefirst processing element identity calculated by dispatcher 275identifies a processing element that has the lightest load among theplurality of processing elements. In one embodiment, the load is basedon processor idle time of the processing element. In one embodiment, theload is based on active sessions for the processing element. In oneembodiment, network address selector 277 obtains load from a processingelement over an Application Programming Interface (API). In oneembodiment, network address selector 277 obtains load from the memorymodule of a processing element. In one embodiment, the proxy networkaddress is selected such that the second processing element identitycalculated by dispatcher 275 identifies a processing element that hasthe lightest load among the plurality of processing elements.

In one embodiment, the proxy network address is selected such that thefirst processing element identity calculated by dispatcher 275identifies a processing element with a functional role. In oneembodiment, the function role includes the processing of a securitypolicy. In one embodiment, network address selector 277 obtains thefunction role of a processing element through a registration process, oran Application Programming Interface (API). In one embodiment, networkaddress selector 277 obtains the functional role from the memory moduleof the processing element.

FIG. 3 illustrates a dispatching process.

Dispatcher 375 calculates a processing element identity based on twonetwork addresses obtained from a data packet 385 of session 360.Session 360 includes host side session 369 and server side session 365.The two network addresses of host side session 369 are server networkaddress and host network address. The two network addresses of serverside session 365 are proxy network address and server network address.Dispatcher 375 calculates to the same processing element identity forhost side session 369 and server side session 365.

In one embodiment, dispatcher 375 calculates based on a hashingfunction.

In one embodiment, dispatcher 375 computes a sum by adding the twonetwork addresses. In one example, dispatcher 375 computes a sum byperforming a binary operation, such as an exclusive or (XOR) binaryoperation, or an and (AND) binary operation, onto the two networkaddresses in binary number representation. In one example, dispatcher375 computes a sum by first extracting portions of the two networkaddresses, such as the first 4 bits of a network address, and applies anoperation such as a binary operation to the extracted portions. In oneexample, dispatcher 375 computes a sum by first multiplying the twonetwork addresses by a number, and by applying an operation such asaddition to the multiple.

In one embodiment, dispatcher 375 computes a processing element identityby processing on the sum. In one embodiment, there are 4 processingelements in security gateway 370. In one example, dispatcher 375extracts the first two bits of the sum, and interprets the extracted twobits as a numeric number between 0 and 3. In one example, dispatch 375extracts the first and last bit of the sum, and interprets the extractedtwo bits as a numeric number between 0 and 3. In one example, dispatcher375 divides the sum by 4 and determines the remainder of the division.The remainder is a number between 0 and 3.

In one embodiment, security gateway 370 includes 8 processing elements.Dispatcher 375 extracts 3 bits of the sum and interprets the extractedthree bits as a numeric number between 0 and 7. In one example,dispatcher 375 divides the sum by 8 and determines the remainder of thedivision. The remainder is a number between 0 and 7.

In one embodiment, a network address includes an IP address and asession port address. Dispatcher 375 computes a sum of the IP addressesand the session port addresses of the two network addresses.

Though the teaching is based on the above description of hashingfunctions, it should be obvious to the skilled in the art to implement adifferent hashing function for dispatcher 375.

FIG. 4 illustrates a proxy network address selection process.

Network address selector 477 selects a proxy network address 487 for ahost network address 483. In one embodiment, host network address 483includes a host IP address 484 and a host session port address 485;proxy network address 487 includes a proxy IP address 488 and a proxysession port address 489. Proxy network address 487 is selected suchthat dispatcher 475 calculates to the same processing element identityon host side session 469 and server side session 465.

In one embodiment, the selection process is based on the dispatchingprocess, illustrated in FIG. 3. In one example, dispatcher 475 uses themethod of computing the sum of two IP addresses, and two session portaddresses, and then divides the sum by 4. In one embodiment, networkaddress selector 477 first selects proxy IP address 488. Network addressselector 477 then selects proxy session port address 489 such that whenusing the method on server network address 490 and host network address483 dispatcher 475 calculates the same processing element identity aswhen using the method on server network address 490 and proxy networkaddress 487.

In one example, dispatcher 475 computes a sum from a binary operator XORof the two network addresses, and extracts the last 3 digits of the sum.Network address selector 477 selects a proxy session port address 489that has the same last 3 digits of the host session port address 485.

In one embodiment, security gateway 470 performs network addresstranslation process for a plurality of existing sessions. Networkaddress selector 477 checks if the selected proxy network address 487 isnot used in the plurality of existing sessions. In one embodiment,security gateway 470 includes a datastore 479. Datastore 479 stores aplurality of proxy network addresses used in a plurality of existingsessions. Network address selector 477 determines the selected proxynetwork address 487 is not used by comparing the selected proxy networkaddress 487 against the stored plurality of proxy network addresses andnot finding a match.

In one embodiment, a processing element includes network addressselector. A processing element receives a data packet assigned bysecurity gateway based on a processing element identity calculated bydispatcher. In one embodiment, the processing element determines thatthe data packet includes a session request. The network address selectorin the processing element selects a proxy network address based on thehost network address in the session request as illustrated in FIG. 4.

In one embodiment, a particular first processing element includesnetwork address selector. A second processing element without networkaddress selector receives a data packet and determines that the datapacket includes a session request. The second processing element sendsthe data packet to the first processing element using, for example, aremote function call. The first processing element receives the datapacket. The network address selector selects a proxy network addressbased on the host network address in the session request.

In one embodiment, datastore is implemented in the memory module of aprocessing element. In one embodiment, the plurality of proxy networkaddresses in datastore are stored in each of the memory modules of eachof the processing elements. In one embodiment, the plurality of proxynetwork addresses in datastore are stored in the memory modules in adistributive manner, with the proxy network addresses used in thesessions processed by a processing element stored in the memory moduleof the processing element.

In one embodiment, security gateway includes a memory shared by theplurality of processing elements. Security gateway partitions the sharedmemory into memory regions. A processing element has access to adedicated memory region, and does not have access to other memoryregions.

In one embodiment, security gateway includes a central processing unit.In one embodiment, the central process unit includes a plurality ofprocessing threads such as hyper-thread, micro-engine or otherprocessing threads implemented in circuitry such as application specificintegrated circuit (ASIC) or field programmable gate array (FPGA). Aprocessing element is a processing thread.

In one embodiment, a central processing unit includes a plurality ofmicro-processor cores. A processing thread is a micro-processor core.

In one embodiment, a security policy is for virus detection or blocking.In one embodiment, a security policy is for phishing detection orblocking. In one embodiment, a security policy is for traffic quotaenforcement. In one embodiment, a security policy is for lawful datainterception.

In one embodiment, the NAT process is for a UDP session. In oneembodiment, security gateway receives a UDP packet. In one embodiment,security gateway determines that the UDP packet is not from an existingsession. Security gateway processes the UDP packet as a session request.

In one embodiment, the NAT process is for an ICMP session. In a similarfashion, security gateway processes an ICMP packet from a non-existingsession as a session request.

Although the present invention has been described in accordance with theembodiments shown, one of ordinary skill in the art will readilyrecognize that there could be variations to the embodiments and thosevariations would be within the spirit and scope of the presentinvention. Accordingly, many modifications may be made by one ofordinary skill in the art without departing from the spirit and scope ofthe appended claims.

1. A method for providing a security gateway, comprising: (a)establishing by the security gateway a host side session between thesecurity gateway and a host, the security gateway comprising amulti-core processor comprising a plurality of central processing unit(CPU) cores; (b) selecting by the security gateway a proxy networkaddress for a host based on a combination of network addresses for thehost side session to result in a calculated first CPU core identity of afirst CPU core of the multi-core processor being the same as acalculated second CPU core identity of a second CPU core of themulti-core processor; (c) using the proxy network address to establishby the security gateway a server side session between the securitygateway and the server; (d) in response to receiving a first data packetfrom the host side session, calculating by the security gateway thefirst CPU core identity and assigning the first CPU core with the firstCPU core identity to process data packets received from the host sidesession according to security policies; (e) in response to receiving asecond data packet from the server side session, calculating by thesecurity gateway the second CPU core identity from a server networkaddress and the proxy network address in the second data packet; (f)assigning the second CPU core with the second CPU core identity toprocess data packets received from the server side session according tothe security policies; (g) processing the second data packet accordingto the security policies by the second CPU core; (h) substituting theproxy network address in the processed second data packet with the hostnetwork address by the security gateway; and (i) sending the processedsecond data packet to the host side session.
 2. The method of claim 1,wherein the calculating (d) comprises: (d1) calculating the first CPUcore identity from a server network address and a host network addressin the first data packet; and (d2) assigning processing of the firstdata packet according to the security policies to the first CPU corewith the first CPU core identity.
 3. The method of claim 2, furthercomprising: (g) processing the first data packet according to thesecurity policies by the first CPU core; (h) substituting the hostnetwork address in the processed first data packet with the proxynetwork address by the security gateway; and (i) sending the processedfirst data packet to the server side session.
 4. The method of claim 1,wherein the selecting (e) is further based on loads of the plurality ofcentral processing unit cores.
 5. The method of claim 4, wherein thefirst central processing unit core has a lightest load among theplurality of central processing unit cores.
 6. The method of claim 1,wherein the selecting (e) is further based on functional roles of theplurality of central processing unit cores.
 7. A security gateway,comprising: a plurality of central processing unit (CPU) cores in amulti-core processor; a network address selector for receiving a sessionrequest for a session between a host and a server, for selecting a proxynetwork address for the host based on a combination of network addressesfor a host side session between the host and the security gateway toresult in a calculated first CPU core identity of a first CPU core ofthe multi-core processor being the same as a calculated second CPU coreidentity of a second CPU core of the multi-core processor, and forestablishing a server side session between the security gateway and theserver using the proxy network address; and a dispatcher for:calculating the first CPU core identity in response to receiving a firstdata packet from the host side session and assigning the first CPU corewith the first CPU core identity to process data packets received formthe host side session according to security policies, calculating thesecond CPU core identity from a server network address and the proxynetwork address in the second data packet, in response to receiving asecond data packet from the server side session, assigning the secondCPU core with the second CPU core identity to process data packetsreceived from the server side session according to the securitypolicies, receiving the processed second data packet from the second CPUcore, substituting the proxy network address in the processed seconddata packet with the host network address, and sending the processedsecond data packet to the host side session.
 8. The security gateway ofclaim 7, wherein the dispatcher: calculates the first CPU core identityfrom a server network address and a host network address in the firstdata packet; and assigns processing of the first data packet accordingto the security policies to the first CPU core with the first CPU coreidentity.
 9. The security gateway of claim 8, wherein the dispatcherfurther: receives the processed first data packet from the first CPUcore; substitutes the host network address in the processed first datapacket with the proxy network address; and sends the processed firstdata packet to the server side session.
 10. The security gateway ofclaim 7, further comprising a datastore for storing proxy networkaddresses for existing sessions, wherein the network address selectordetermines the proxy network address is not used in an existing sessionby comparing the proxy network address against addresses in thedatastore, wherein the network address selector selects the proxynetwork address based on the combination of network addresses for thehost side session.
 11. The security gateway of claim 7, wherein theselecting of the proxy network address is further based on loads of theplurality of central processing unit cores.
 12. The security gateway ofclaim 11, wherein the first central processing unit core has a lightestload among the plurality of central processing unit cores.
 13. Themethod of claim 7, wherein the selecting of the proxy network address isfurther based on functional roles of the plurality of central processingunit cores.